Quinn emanuel trial lawyers

Doolittle, Diane M.

Diane M. Doolittle



Diane Doolittle serves as Co-Chair of the firm's National Trial Practice Group. She litigates and tries high-stakes complex commercial, intellectual property and white collar cases.  Ms. Doolittle has tried more than 70 cases and won 92%. She is repeatedly recognized as one of the leading trial lawyers in the United States. In 2012, she was named a "Top Female Trial Attorney," one of only 15 women nationally to be selected for this inaugural honor by Law360. For seven of the last eight years, she has been selected by the San Francisco and Los Angeles Daily Journals as a "Top Women Lawyer" in California. In 2013, 2016, 2017, and 2019 she was recognized by The Recorder as one of the "Women Leaders in Tech Law."     

Ms. Doolittle has tried a wide variety of complex disputes with tens or hundreds of millions of dollars in dispute in state and federal courts across the country, including misappropriation of trade secrets, trademark, antitrust, fraud, breach of contract, breach of fiduciary duty, unfair competition and insurance coverage. She has tried multiple employment cases involving allegations of discrimination, harassment and wrongful discharge. Ms. Doolittle also has extensive experience trying criminal cases, from street crimes to white collar crimes. Because of her unique trial skills, Ms. Doolittle is often engaged in the weeks or months before trial, specifically to act as trial counsel.

As a former prosecutor, Ms. Doolittle brings special expertise to, and spends a significant amount of time, defending corporations, officers and directors in parallel civil and criminal matters, including under the federal securities laws, the False Claims Act, and the FCPA. She also litigates intellectual property disputes, including cutting-edge disputes over the intersection of intellectual property law and the Internet.

Ms. Doolittle is also a go-to lawyer for sensitive, high profile cases that require the development and coordination of civil, criminal, media and public relations strategies, which often involve coordinating and interfacing with multiple law firms and constituencies.   

Ms. Doolittle lectures extensively about trial practice. Currently, she teaches trial advocacy and deposition practice at Stanford Law School.

  Notable Representations


  • Won a nearly $100 million jury verdict against L’Oreal on behalf of beauty company start-up Olaplex, the inventor of a patent protected method for protecting and repairing hair during the bleaching process in a patent and trade secrets trial in the District of Delaware.
  • Won a plaintiff’s judgment of $23+ million for medical device company after two-week trial in Northern District of California against former director for breach of fiduciary duty.
  • Successfully defended Pfizer in two lengthy trade secret trials lasting over 2 months in Santa Clara County Superior Court; defeated 152 of 159 trade secrets claims and reduced damages from a claim for $1 billion in damages, to a jury award of $165,000 in damages.
  • Won two separate trials in Orange County Superior Court for a billionaire client accused of wrongfully terminating his estate manager in retaliation for testifying against him in grand jury proceedings, as well as denying her overtime pay.  
  • Won a defense verdict following a jury trial in Los Angeles County Superior Court on behalf of a billionaire client who was accused of fraudulently denying his children  more than $150 million in child support.  Argued and successfully defended defense verdict before the California Court of Appeal. 
  • Won a defense judgment in federal court in the Central District of California on behalf of The Home Depot in a case alleging misappropriation of confidential and trade secret information.
  • Won a defense verdict in a two-week antitrust trial seeking hundreds of millions in damages in the Southern District of New York on behalf of a national lawn and garden marketing company.
  • Won $10+ million jury verdict in a two week trial for breach of contract in the Southern District of Ohio on behalf of a national lawn and garden marketing company. 
  • Won a defense award following a JAMS international arbitration on behalf of Oracle Corporation, where Oracle's former Saudi Arabian joint venture partner had sued for fraud and breach of contract under Saudi law seeking tens of millions of dollars.
  • Won a defense verdict following a six week jury trial in San Francisco Superior Court on behalf of investment bank Jefferies & Co. in which the plaintiff, a highly compensated investment banker, alleged wrongful termination and discrimination. The verdict was nominated for "Verdict of the Month" by The National Law Journal.   
  • Won a plaintiffs’ judgment on all claims after trial in Los Angeles County Superior Court on behalf of the CEO of a large, public company in a wrongful death case where the plaintiff’s daughter died of a drug overdose after defendant failed to summon medical care.
  • Won a defense award following a six week trial in an administrative enforcement action brought by the California Department of Managed Health Care against Kaiser Foundation Health Plan. 
  • Obtained a favorable settlement after six weeks of jury trial in Fresno County Superior Court on behalf of a large security company and its CEO accused of fraud, breach of partnership, and breach of contract.
  • Obtained a favorable settlement after four weeks of jury trial in Sacramento Superior Court for a national insurance company, where plaintiff claimed that the insurance company failed to reimburse $135 million incurred in cleaning up a major Superfund site.

Other Notable Representations

  • Representing Google in connection with multiple lawsuits involving Adsense and Ad Words.
  • Representing Google, PayPal and Stripe defending a putative class action under California's Unruh Civil Rights Act.
  • Represented eBay in lawsuit alleging misappropriation of trade secrets by internet classifieds company craigslist.  
  • Represented Johnson & Johnson subsidiary Scios Inc. in connection with parallel civil and criminal actions for alleged violations of the Food Drug and Cosmetic Act and the False Claims Act for alleged off label drug promotion.
  • Represented Actelion Pharmaceuticals Inc. in connection with government investigation into alleged off label promotion in contravention of the Food Drug and Cosmetic Act and the False Claims Act which ended with government closing investigation and declining to pursue changes.
  • Represented the Special Committee of the Board of Directors of Apple, Inc. in an internal investigation into the alleged backdating of stock option grants received by Apple executives including Steve Jobs, as well as the Apple Special Litigation Committee in related shareholder derivative lawsuits and class action litigation.
  • Represented Co-founders of Marvell Technology Group in class action and related shareholder derivative lawsuits and parallel regulatory investigations.
  • Defended Dr. Henry T. Nicholas, the founder and former CEO of Broadcom Corporation, in a federal criminal prosecution. Obtained dismissal of all charges.
  • Represented Yandex, Russia’s most popular search engine, in a copyright infringement action brought by adult entertainment publisher Perfect 10 involving allegations of direct and secondary copyright infringement related to Yandex’s Russian internet search and hosting services.
  • Represented multiple high net worth individuals in connection with dissolution proceedings.


  • Boalt Hall School of Law, University of California, Berkeley
    (J.D., 1989)

  • Institut d'Etudes Politiques, Aix-en-Provence, France
    (Certificate, 1986)

  • Princeton University, Woodrow Wilson School of Public and International Affairs
    (A.B., cum laude, 1985)


The State Bar of California; The State Bar of Colorado

  Prior Associations

  • Office of the District Attorney, Santa Clara County:
    • Senior Trial Attorney, 1993-1998

  • Law Clerk to the Hon. Ronald M. Whyte:
    • United States District Court, Northern District of California, San Jose Division, 1992 


  • In 2019, Ms. Doolittle was named to the Daily Journal’s list of “Top Trade Secrets Lawyers".
  • In 2012, Ms. Doolittle was named one of the fifteen “Top Female Trial Lawyers in America” by Law360.
  • From 2009 to 2019, Ms. Doolittle was selected by the San Francisco and Los Angeles Daily Journals as one of the “Top Women Lawyers” in California.
  • In 2013, 2016, 2017, and 2019, Ms. Doolittle was selected by The Recorder as one of the “Woman Leaders in Tech Law.”
  • From 2004 to 2019, she has been selected each year as a Northern California “Super Lawyer” by California Lawyer Magazine.

Professional Activities

  • Association of Business Trial Lawyers (ABTL):  President 2016, Vice President 2015, Treasurer 2014, Secretary 2013, Program Chair 2009 and 2010, Board of Governors 2007 to 2016
  • Instructor, Stanford University Law School, Trial Advocacy Program, 2000 to present
  • Northern District of California Standing Committee on Professional Responsibility, 2010 to 2014
  • Lawyer Representative, Ninth Circuit Judicial Conference, 2005 - 2007 
  • Lawyer Representative, Northern District of California, 2005 - 2007  
  • Instructor, National Institute of Trial Advocacy (NITA), 1994 - 2009
  • Adjunct Professor, Santa Clara University School of Law, Trial Advocacy, 1996 - 1999